Implant-Supported Overdenture Calculator

It reflects the 2002 McGill Consensus Statement, a published expert consensus recommending a two-implant mandibular overdenture as the first-choice standard of care for the edentulous mandible. It is a recommended baseline treatment, not an absolute rule that fewer implants can never work or that more implants are wrong for a given case.

Maxillary bone is typically less dense than mandibular bone, and there is no cross-arch equivalent to the McGill statement for the maxilla -- published randomized trials instead compare 4-implant and 6-implant maxillary overdenture protocols directly rather than settling on one number. This calculator uses 4 as its maxillary minimum, which sits at the lower end of that studied range.

No -- in this calculator, Bone Quality (the Misch D1-D4 classification) only affects Stability score, not Est. total cost. The cost calculation depends on Number of implants, Attachment type, and the fixed denture cost, since bone density affects how well an implant integrates and functions, not the parts-and-labor cost of the prosthesis.

No -- each attachment type carries a single assumed newton value in this calculator as a simplified planning figure, not a verified universal constant. Real retention force varies by manufacturer, the specific insert or ball housing used, its wear state, and how precisely the attachment fits, so treat Total retention force as a rough comparison between attachment types rather than a lab-measured number.

It blends how far Number of implants exceeds the arch's minimum, the attachment type's assumed rigidity (bar scores highest, ball/o-ring lowest), and Bone Quality (denser bone scores higher) into one 0-100 figure. It is meant as a quick relative comparison across scenarios, not a clinically validated stability index.